Buffing or polishing machine



y 1943. E. MURRAY 2324;416

BUFFING OR POLISHING MACHINE Filed April 22, 1941 5 Sheets-Sheet 3 INVENTOR fr'fie fg Murray ATT EY5.

y 3, 1943. E. E. MURRAY 2,324,416

BUFFING 0R POLISHING MACHINE Filed April 22, 1941 5 Sheets-sheaf, 4

INVNTOR E7765} 2?: Murray 'ATTORN 5.

July 13, 1943. E. E. MURRAY BUFEING OR POLISHING MACHINE 5 Sheets-Sheet 5 INVENTOR z rvieszznu rd y Filed April 22, 1941 Patented July 13, 1943 UNITED STATES PATENT OFFl-CE BUFFING R POLISHING MACHINE Ernest E. Murray, Detroit, Mich.

Application April 22, 1941, Serial No. 389,790

(Cl. l166) 131Claims.

The present invention relates to finishing or polishing machines and particularly relates to improvements in the heads for mounting polishing machines.

One of the primary objects of the present invention is to provide improvements in power driven finishing or polishing machines whereby, regardless of the angle of the polishing wheel to the work and regardless of the contour of the work, the wheel is caused to follow the proper path in contact with the work as the work and wheel mounting are moved with respect to each other.

Another object of the invention is to provide improvements in machines of the type mentioned, in which the wheel may be set with respect to the work so that such wheel is caused to follow a predetermined path in contacting the work to compensate for shifting of the point of tangency of the wheel in contacting the work at different points therealong.

Another object of the invention is to provide improvements in machines of the type mentioned, in which the wheel may be set with respect to a cambered Work article so that such wheel is caused to follow a predetermined path in contacting the Work along the camber to compensate for wheel misalignment due to shifting of the point of tangency of the wheel and/or due to changes in spindle angle as the wheel moves along the camber of the article in contact therewith.

Another object of the invention is to provide improvements in mountings for power driven polishing wheels for polishing elongated articles having a longitudinal camber therein and having a transversely inclined surface in which, when the wheel is disposed at an angle between the vertical and horizontal, it is caused to follow a predetermined path in contacting the work to compensate for shifting in the tangency of the wheel in contacting the Work at difierent points therealong.

A further object of the present invention is to provide a universal, power driven polishing machine in which the wheel properly contacts the work at all points along the work whether such wheel is disposed on a vertical, a horizontal, or an inclined axis.

A further object of the invention is to provide improvements in machines of the type mentioned which are so constructed that it will permit a wheel to hunt within practical limits so that the contour of the wheel may properly align itself with the contour of the work.

Amore specific object of the invention is to provide improvements 'in the means for adjustably mounting the axis of the .polishing wheel so that such axis may be disposed horizontally, vertically, or on an incline of the vertical, and

when disposed on the incline may be so set with respect'to the work 'as'to cause it to follow a predetermined .path to compensate for shifting in theta'ngency of the wheel 'in contacting the work at difierent points 'therealong.

Another object of the present invention is to provide improvements in machines of the type mentioned, in which improved means are provided for urging the wheel toward the work into engagement therewith when such wheel is mounted to rotate on a'vertical axis.

Other objects of the invention will become apparent from the following specification, the

drawings relating thereto, and the claims hereinafterse't forth.

In the drawings, in which like numerals are used' 'to designate like parts in the several views throughout:

Figure 1 isa front perspective view of a power driven polishing machine employing features of the present invention and showing the machine set with the wheel axis in a substantially horizontal position;

Fig. 2 is an end elevational view'of the machine shown in Fig. 1 from the right hand side thereof, and showing the wheel axle tilted at an incline to the vertical;

Fig. '3 is an enlarged cross-sectional view taken substantially along the line 3-3 of Fig. 1;

Fig.4 is a top plan view-of the structure-shown in Fig. 1;

Fig. 5 isa front elevational view of the top portion of the structure shown in Fig. 1;

Fig. 6 is an enlargedcross-seotional View taken substantially along the line 66 of-Fig. 5;

Fig. 7 is a rear perspective view of the structure shown in Fig. 1,-showing the wheel spindle in a vertical position and illustrating an attachment in position for urging the wheel toward the work When the-spindle is so disposed;

Fig. 8 is an enlarged top plan view taken substantially along the line 8-8 of-Fig. 7.;

action of the present invention when engaging an elongated, bowed workpiece; and

Fig. 12 illustrates an incorrect action, for purpose of comparison, so that the present invention may be readily appreciated.

It has been the practice in polishing articles having an elongated camber therein, such as automobile bumpers, to mount such articles on an endless conveyer and carry the articles past a plurality of power driven polishing machines which are disposed beside the conveyer at spaced points therealong. Such machines are so positioned that the polishing wheels thereof engage the surface of the bumper to finish or polish such surface as the articles are passed thereby. It was found in such practice that the surfaces of the bumpers were not evenly polished and often contained scratches or other forms of imperfections which were caused by the polishing wheels and which usually had to be remedied by hand polishing. It was not until the present invention that the cause of these defects in this above mentioned practice was realized nor could such causes be corrected until the present invention.

It was discovered that the cause of the imperfect polishing was due to the shifting of the point of tangency of the polishing wheel in contacting the cambered work article at different points therealong and was also due to the changes in the spindle angle as the wheel moves along the camber of the article in contact therewith. According to the present invention, a construction is provided in which the polishing wheel may be so disposed with respect to the work, regardless of whether it is on a vertical, inclined, or horizontal axis, so that the polishing wheel is caused to follow a predetermined path in contacting the work along the camber thereof to compensate for wheel misalignment due to this shifting of the point of tangency of the wheel and/or due to changes in spindle angle as the wheel moves along the camber of the article in contact therewith.

For a better understanding of the invention,

reference may be had to the drawings and particularly to Figs. 1 through thereof in which the polishing wheel spindle is illustrated as being disposed in various positions. Such polishing machine comprises a base l6 having an upstanding standard mounted thereon for lateral adjustment along ways on the base. The standard is formed of a plurality of telescoping sections [2, l4, and I6. A jack 18 having operating elements 20 is associated with the telescoping sections and engages with the operating members connected to the lower end of the telescoping section l6, so that such upright standard may be adjusted as to height.

A bearing 22 is mounted within standard section I 6 and receives thereon an upright pivot pin pin 24 which projects upwardly through the top thereof and which is connected to a forked or bifurcated mounting member 26, so that such member 26 may pivot with respect to the standard about the longitudinal axis of pin 24.

A power driven polishing wheel 28 is mounted to the standard through the yoke arm 26 in a manner now to be described. Such polishing wheel is fixed to a driving spindle 36 to be driven thereby; and such spindle 30 is mounted within a tubular frame member 32 having bearings 34 disposed at the ends thereof and through which the shaft 38 extends. The member 32 is secured to the ends of longitudinally extending frame arms 36 which may be of channel section and which may be bowed as indicated at 38 in order to provide clearance when such frame is tilted to certain of its positions. The opposite ends of the frame arms 36 are connected to a mounting plate 40 adjacent the upper edge thereof.

A gear housing 42 is fixed to the forward face of the plate member 40, or may be formed integral therewith, and an annular clamping plate 44 is fixed to the front annular edge of the housing 42 by means of bolts 46. A gear or worm wheel 48 is disposed within the housing 42 and is rotatably mounted upon a stub shaft 50 which is mounted to the rear face of the housing 42 or to the plate 46. A worm 52 is mounted in the housing 42 in mesh with the gear 48 and has a projecting end 54 which may be engaged by a suitable tool so that the worm 52 may be turned, thereby turning the gear 48 with respect to the housing 42.

The plate 48 is provided with an inwardly projecting annular flange 56 (Fig. 5), which is adapted to abut against the face of the gear 48 so that said face plate may be drawn tightly against the gear to act as a brake and to fix such gear in position.

The gear 48 is formed with a pair of integral ears or lugs 58 which are normal to the face of the gear and which have aligned bearing apertures 60 therein so that; such lugs 58 project forwardly through the opening in the housing 42 and through the opening in the clamping ring 44. A cross arm 62 has a transverse pivot shaft 64 pivotally received within the bearing apertures 66 of the projections 48. Such arm 62 has an integral or fixed pin 66 connected thereto which is disposed at substantially a right angle to the.

axis of the shaft 64; and such pin 66 is received through aligned openings in the forked arms of the bifurcated member 26.

It will thus be seen that the wheel 28, together with the spindle 38 and the frame 36, may be pivoted with respect to the supporting standard about the pivots 64. r

The shaft or pin 66 projects through the arms of the bifurcated element 26 into a gear housing 10 which may be mounted u on the forward arm of the member 25. A gear or worm wheel 12 is disposed within the housing 10 and keyed to the shaft 56. Such gear 12 may be rotated with respect to the housing by means of a worm 14 which is mounted within the housing in mesh with the gear 12 and which has a projecting end 16. Such projecting end may be engaged by a suitable tool for the purpose of rotating the worm and for therefore rotating the gear '12 and the shaft 66, together with the shaft 64, with respect to the standard. It will thus be seen that when the shaft 66 is rotated, the lugs 58 are caused to rotate through their connection with the pivot shaft 64 so that the housing 42, together with the frame members 36 and the spindle 30, are correspondingly rotated.

The driving means for the wheel 28 comprises an electric motor 18 which is secured to a mounting plate 80. Such mounting plate is hingedly connected to the upper end of the plate member 46 by means of a suitable hinge and pintle construction 82. Motor 18 has a drive shaft 84 to which a pulley 86 is keyed, and a plurality of driving belts 88 are trained about the pulley 86 and are also trained about a drive pulley 98 which is keyed to the driving spindle 30. In order to tighten such belts, a set screw, or screws, 92 is received through a tapped opening in plate member 48 and is so disposed that the inner end thereof abuts against the back of mounting plate 59. It will thus be seen that by adjusting the set screws 92, the belts 88 may be tightened.

In order to permit a slight hunting movement of the wheel 28, or a slight lateral movement'of such wheel, a box-like bracket 96 is clamped to the standard it by means of a split clamp '98 which engages the section It adjacent the upper end thereof. A member iill, having a depending finger N32, is fixed to one side of the base of the bifurcated member 26 and is so positioned that the finger m2 projects downwardly within the housing 96. Such flnger I02 is provided with an opening m4 therethrough adjacent'the lower end thereof which receives therein the stub ends of pins ms. Such pins "it have annular flanges Hi8 thereon which abut against the opposite faces of the member 482 with pins projecting outwardly of such flanges Hi8. Spiral spring H abut against the flanges M8 with the pin projections Q preventing displacement of such springs and the opposite ends of such springs abut against annular stops H2 which are adjustably mounted to the sides of the housing 96 by means of adjustable screws 5 Hi. inwardly projecting portions which prevent displacement of the outer ends of springs Hi. It will thus be seen that the depending finger 102 is resiliently urged to a central position through the action of the springs 1 iii, but that a slight movement is permitted due to the resiliency of such springs, in order to permit a slight hunting action of the wheel 28.

The spindle, together with the wheel 28, is counterbalanced about the pivot 64, whe the spindle is in a horizontal or inclined position, by means of removable scale weights H5 which are provided with radial slots through the periphery thereof so that such weights may be mounted upon a transversely extending plate member l !8. Such weight are preferably chosen so that the weight of the motor is slightly overbalanced and so that the wheel 28 is urged into engagement with the work.

Such weights H6 are used only when the spindle is in a horizontal or inclined position, and when the spindle 39 is disposed in a vertical position, as shown in'Figs. 7, 8, and 9, another attachment is mounted to the machine for urging the wheel against the work. Such other 'attachment includes a boxlike mounting bracket 12%] which may be removably attached to the outer edge of the mounting bracket 96. Such bracket I26 is formed with a pair of spaced bearings !22 which receive therethrough a pivot shaft I24.

Such pivot shaft 52 has a normally horizontal arm I25 fixed to one end thereof and to which suitable scale weights I28 may be hung within a notch l3li formed in the opposite end of the arm I26. Another, normally vertical, arm I32 is fixed to the opposite end of the pivot shaft 526. The upper end of the rm I32 is connected to one of the frame members 36 by means of a link I38 which is formed with a universal joint 14%? therein. The one end of the link 133 is pivotally connected to the upper end of arm I32 and the opposite end of the link I38 is pivotally connected to one of the frame members 36. It will thus be seen that the scale weights E28 act on the frame members 36, through members I38, E32, and 124, to urge the wheel against or toward the work. The universal connection Hi8 permits this action to take place as the spindle pivots about the upright standard.

In Fig. 10, the machine is illustrated as being The members H2 also have worm 52.

disposed beside an endless conveyer Hi4 which has a workpiece 1'46 mounted thereon. Such workpiece I46 may beanautomobile bumper or the like and, as illustrated, has a longitudinal camber therein and has curved surfaces Hi8 whi'ch'are transversely curved in the direction of movement of the article 146. The wheel 28 is illustrated as engaging -a portion of the side-of 'the surface MS with the spindle 3!! inclined to'the vertical.

It wil1 be understood that the wheelie has the contour of that portion-of the workpiece that it engages and that such wheel'rotates at a high speed in contact with the workpiece as the workpiece is moved past the polishing machine on the moving conveyer I44.

It will also be'understood that the various machines which are disposed along the conveyer have their spindle a'Xes at various angular positions with respect to the work. Each wheel engages only a limited transverse position of the article being worked upon and certain of the spindles will be on a horizontal axis, others will be inclined to the vertical, and others may be vertical, of course depending upon the contour of the particular piece beingfinished.

In the operation of the machine of the present invention, when the polishing wheel is positioned to engage the top or substantially horizontal portion of the workpiece, the spindle 39 is disposed substantially horizontally and the pivot 54 is also disposed substantially horizontally. As the workpiece is carriedpast that particular machine by the conveyer', the point of tangency of the wheel with the work lies in a vertical plane, which is parallel to the direction of travel of the work so that there is no lateral shifting of the point of tangency on the workpiece as the cambered workpiece moves past the machine. The pivotal movement of the spindle about the parallel pivot pinfi i will cause the point of tangency of the wheel with the work to remain in the aforementioned vertical plane.

When the spindle 30 is disposed vertically, the pivot pin 64 is disposed substantially parallel thereto and there is no need to compensate for any shift inthe point of tangency.

This positioning of the spindle either horizontally, vertically, or on an incline to the vertial, is accomplished through rotation of the worm 14. The pivot 64 may be adjusted with respect to the axis of the spindle 30 through the It will thus be seen that the relative angles of the axes of pin 64 and spindle 3%! may be varied with respect to each other.

When the spindle 30 is inclined to the vertical so as to engage an inclined portion of the workpiece, as shown in Figs. 10, 11, and 12, according to the present invention the pivot 65 is positioned with respect to the angle of the spindle 30 so as to compensate for the shift in the point of tangency and/or the variations in the angular position of the spindle 30 with respect to the work as the cambered workpiece is moved past the polishing machine. For a better understanding of this, reference may be had to Figs. 11 and 12 in which this is diagrammatically illustrated. The wheel 28 is shown inclined to the vertical and is shown in contact with the workpiece 36 at positions A and B. It will be seen by comparing these two figures that the point of tangency on the wheel '28 is different at point A than it isat point B. It will thus be seen that as the workpiece -46 moves from position A to position B, the point of tangency of the wheel therewith shifts. These points of tangency, due to the inclination of the wheel, are in different vertical planes in the direction of travel of the work.

With the pin 64 in a horizontal position, as shown in Fig. 12, as the wheel 28 travels up over the camber of the workpiece I46 from position A to position B, the wheel 28 pivotsabout pin 64; so that with the wheel in proper engagement at point A, the Wheel in moving to the position shown at B would not properly engage the workpiece. This will be seen in the righthand view of Fig. 12 wherein there is a gap between the surface of the wheel and the surface of the workpiece and such workpiece is contacted by the wheel only along one edge thereof. This misalignment, with resultant scratches and imperfections in the workpiece, is due to this shifting of the point of tangency and due to the variations in the angular position of the spindle 30 in moving from position A to position B.

These are compensated for in Fig. 11 by shifting the axis of shaft 64, as indicated in the righthand view of Fig. 11. It will then be seen that in moving from position A to position B, the spindle and wheel pivot about the axis 64, which, in this case, is tilted slightly off the horizontal in a clockwise direction. Such adjustment of the pivot 64 compensates for the shifts in the points of tangency and the variations in the angular position of the spindle 30 so that at all positions between positions A and B, the wheel 28 is in proper contact with the workpiece.

It has been found that machines of the present invention, with the multiple adjustments of the spindle and pivot axes, may be very quickly set up to compensate for the above mentioned variations in tangency and shift of the spindle angle when working on complicated contours as in polishing automobile bumpers. The extent of adjustment is a matter of observation for a trial piece of the machines may be quickly set by the skilled operators.

While only one specific embodiment of the present invention has been here illustrated, it is to be understood that formal changes may be made in the specific embodiment shown without departing from the spirit and substance of the broad invention, the scope of which is .commensurate with the appended claims.

What is claimed is:

1. In polishing apparatus wherein an article having a longitudinal camber therein and having portions of the surface thereof disposed at an incline to the vertical transversely thereof is disposed longitudinally on a conveyor for line movement therewith, the combination of a polishing machine comprising a power driven spindle, a polishing wheel mounted thereon and driven thereby, and means mounting said spindle at an incline to the vertical for movement when said wheel engages said article along the camber thereof, said last named means including restricting means for controlling the movement of said spindle and the wheel thereon, said restricting means being so constructed that the point of tangency of said wheel with the article is caused to follow in a vertical plane parallel to the direction of travel of the article.

2. In a polishing machine, a power driven spindle, a polishing wheel mounted thereon and driven thereby, a support, means pivotally mounting said spindle on said support, said last named means including a pivot fulcrum for said spindle, means for adjustably setting said spindle on a horizontal, vertical, or inclined position, and means for adjustably varying the axis of the pivot fulcrum with respect to the axis of the spindle.

3. In a polishing machine, a power driven spindle, a polishing wheel mounted thereon and driven thereby, a support, means pivotally mounting said spindle on said support, said last named means including a pivot fulcrum for said spindle, means for adjustably setting said spindle together with said pivot fulcrum on a horizontal, vertical, or inclined position, and means for adjustably varying the axis of the pivot fulcrum with respect to the axis of the spindle.

4. In a polishing machine, an upright standard, a power driven spindle, a polishing wheel mounted thereon and driven thereby, an arm member having the spindle mounted on one end thereof, and means pivotally connecting the opposite end of said arm to said standard, said last named means including means providing a pivot fulcrum for said arm about which said spindle pivots, adjustable means for setting said spindle at a predetermined position with respect to the vertical, and means for adjustably varying the fulcrum axis with respect to the axis of the spindle.

5. In a polishing apparatus wherein an elongated article having a longitudinal camber therein and having portions of the surface thereof disposed at an incline to the vertical is disposed longitudinally on a conveyor for line movement therewith, the combination of a polishing machine mounted adjacent said conveyor comprising a power driven spindle, a polishing wheel mounted thereon and driven thereby, a support, means pivotally mounting said spindle on said support, said last named means including a pivot fulcrum for said spindle so that said spindle together with said wheel is moved about said fulcrum in engaging said article along the camber thereof, means adjustably setting said spindle together with said fulcrum on a horizontal, ver tical, or inclined position, and means for adjustably varying the axis of the pivot fulcrum with respect to the axis of the spindle, to thereby compensate for any shifting of the point of tangency of the wheel in contacting the article along the camber thereof.

6. In a polishing apparatus wherein an elongated article having a longitudinal camber therein and having portions of the surface thereof disposed at an incline to the vertical is disposed longitudinally on a conveyor for line movement therewith, the combination of a polishing machine comprising a power driven spindle, a polishing wheel mounted thereon and driven thereby, a support, means pivotally mounting said spindle on said support, said last named means including a pivot fulcrum for said spindle so that said spindle, together with said wheel, is pivoted about said fulcrum in engaging said article along the camber thereof, and means for adjustably setting said spindle and said fulcrum at a predetermined position with respect to the vertical and means for varying the axis of the pivot fulcrum and the axis of the spindle with respect to each other to thereby compensate for any shifting of the point of tangency of the wheel in contacting the article along the camber thereof.

7. In a polishing machine, an upright standard, a power driven spindle, a polishing wheel mounted thereon and driven thereby, an arm member having a spindle mounted on one end thereof, and means pivotally connecting the opposite end of said arm to said standard, said last named means including means providing a pivot fulcrum for said arm about which said spindle pivots in one direction, a pivot element having its axis substantially normal to the axis of said fulcrum about which said spindle pivots in another direction, means to adjust said spindle about the pivot element axis and means to adjust said fulcrum axis with respect to the axis of the spindle.

8. In a polishing machine, an upright standard, a power driven spindle, a polishing wheel mounted thereon and driven thereby, an arm member having a spindle mounted on one end thereof, and means pivotally connecting the opposite end of said arm to said standard, said last named means including means providing a pivot fulcrum for said arm about which said spindle pivots in one direction, a pivot element having its axis substantially normal to the axis of said fulcrum about which said spindle pivots in another direction, means to adjust said spindle about the pivot element axis to a set position with respect to the vertical, and means to adjust said fulcrum axis with respect to the axis of the spindle.

9. In a polishing machine, an upright standard, a power driven spindle, a polishing Wheel mounted thereon and driven thereby, an arm member having a spindle mounted on one end thereof, and means pivotally connecting the opposite end of said arm to said standard, said last named means including means providing a pivot fulcrum for said arm about which said spindle pivots in one direction, a pivot element having its axis substantially normal to the axis of said fulcrum about which said spindle pivots in another direction, means to adjust said spindle about the pivot element axis to a set position with respect to the vertical, and means independent of said last named means to adjust said fulcrum axis with respect to the axis of the spindle.

10. In a polishing machine, an upright standard, a power driven spindle, a polishing wheel mounted thereon and driven thereby, an arm member having a spindle mounted adjacent one end thereof, and means pivotally connecting said arm to said standard for pivotal movement of said arm about a vertical axis and lateral movement of said wheel with respect to the axis of said standard, said last named means including means limiting such pivotal movement and urging said wheel to a predetermined position to thereby permit limited lateral movement of said wheel.

11. In a polishing machine, an upright standard, a power driven spindle, a polishing wheel mounted thereon and driven thereby, an arm member having a spindle mounted adjacent one end thereof, and means pivotally connecting said arm to said standard for pivotal movement of said arm about a vertical axis and lateral movement of said wheel with respect to the axis of said standard, said last named means including resilient means limiting such pivotal movement and resiliently urging said wheel to a predetermined position to thereby permit limited lateral movement of said Wheel out of said predetermined position.

12. In a polishing machine, an upright standard, a power driven spindle, a polishing wheel mounted thereon and driven thereby, an arm member having a spindle mounted on one end thereof, and means connecting the opposite end of said arm for pivotal movement with respect to said standard, said last named means including means providing a pivot fulcrum for said arm about which said spindle pivots in one direction, a pivot element havng its axis substantially normal to th axis of said fulcrum about which said spindle pivots in another direction, means to adjust said spindle about the pivot element axis and to adjust said fulcrum axis with respect to the axis of said spindle, means pivotally connecting said pivot element to said standard for pivotal movement of said arm and lateral movement of said wheel with respect to the axis of said standard, said last named means including means limiting such last named pivotal movement to thereby permit limited lateral movement of said wheel.

13. In a polishing machine, an upright standard, a power driven spindle, a polishing wheel mounted thereon and driven thereby, an arm member having a spindle mounted on one end thereof, and means connecting the opposite end of said arm for pivotal movement with respect to said standard, said last named means including means providing a pivot fulcrum for said arm about which said spindle pivots in one direction, a pivot element having its axis substantially normal to the axis of said fulcrum about which said spindle pivots in another direction, means to adjust said spindle about the pivot element axis and to adjust said fulcrum axis with respect to the axis of said spindle, means pivotally connecting said pivot element to said standard for pivotal movement of said arm and lateral movement of said wheel with respect to the axis of said standard, said last named means including resilient means limiting such last named pivotal movement and resiliently urging said wheel to a predetermined lateral position to thereby permit limited lateral movement of said wheel.

ERNEST E. MURRAY. 

